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本文系统地讨论了大统一理论的来龙去脉。回顾了大统一理论的发展历史,讨论了其发展现状及存在问题,指出了进一步发展的方向。本文重点介绍了SU(5)和SO(10)两个模型,讨论了Higgs场、规范等级、渐近自由、重正化等问题。文章进而讨论了一些有趣问题,比如提供了对宇宙重子起源的解释、计算了质子衰变寿命、论述了B-L是否守恒以及讨论了中子和中微子可能有的振荡现象等。 相似文献
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"牛顿由于发现了万有引力定律而创立了科学的天文学,由于进行了光的分解而创立了科学的光学,由于建立了二项式定律和无穷理论而创立了科学的数学,由于认识了力的本性而创立了科学的力学."恩格斯的这段话很好地总结了牛顿的科学业绩.为了纪念牛顿在科学上的伟大建树,许多国家发行了多枚一套的邮票. 相似文献
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本文系统地讨论了大统一理论的来龙去脉。回顾了大统一理论的发展历史,讨论了其发展现状及存在问题,指出了进一步发展的方向。本文重点介绍了SU(5)和SO(10)两个模型,讨论了Higgs场、规范等级、渐近自由、重正化等问题。文章进而讨论了一些有趣问题,比如提供了对宇宙重子起源的解释、计算了质子衰变寿命、论述了B-L是否守恒以及讨论了中子和中微子可能有的振荡现象等。 相似文献
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采用控制环量方法设计了一单级涡轮。该方法打破了传统的设计规律,为验证该方法的可靠性进行了模型试验。在宽广的范围内测定了总特性;在设计点附近作了沿叶高效率分布及动叶进、出口速度三角形的测定。本文给出了主要试验结果并作了简要分析。结果表明基本上达到了设计要求,控制环量设计的主要特征得到了验证,该方法基本可行。 相似文献
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介绍了基础激励下机构随机振动响应的理论与分析方法.利用有限元分析软件ANSYS建立了某空间望远镜相关跟踪系统摆镜的有限元模型,并进行了随机振动响应分析.通过分析考察了其承受动力学环境的能力.对计算结果进行了分析.指出了现有结构中的薄弱环节,提出了改进方案,为摆镜的设计提供了重要参考依据. 相似文献
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设计了大气激光通信信道测量系统,利用此系统在不同气象条件下进行了近地视距实验测量并采集了不同天气条件下的实验数据,详细分析讨论了所得实验数据并进行了误差分析.同时实验中获得了大量数据,为进一步完善大气激光信道模型提供了有力的依据. 相似文献
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With a view to get further insight into the integrability of a dynamical system, we investigate the complex invariant for a three-dimensional Hamiltonian system using the extended complex phase space approach (ECPSA) characterized by and . For this purpose the rationalization method is utilized and the invariant obtained is expected to play an important role in the study of the complex trajectories for the system of concern. 相似文献
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Jianwen Wei 《Solid State Communications》2010,150(15-16):777-781
The tunneling conductance in a normal metal/insulator/metal/ mixed wave superconductor (N/I/N/) junction is calculated, where the N/I/N region is a quantum wire. It is found in the single-mode case that the magnitude of the tunneling conductance near zero voltage is enhanced due to the Andreev bound state by quasiparticles with perpendicular and horizontal injection, and the zero-bias conductance varies with ( is the distance from insulating layer to the interface of N/ mixed wave superconductor). Splitting of the zero-bias conductance peak appears in the quantum point contact tunneling spectra for an N/I/N/ junction, and several subgap peaks can split at the same time. On increasing both and the magnitude ratio of the two components for the mixed wave, the subgap resonances exhibit an alternately high and low behavior inside the energy gap. These results are different from those in d-wave and p-wave superconductor junctions. 相似文献
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《Journal of Geometry and Physics》2006,57(1):323-337
We consider the unique Hermitian connection with totally skew-symmetric torsion on a Hermitian manifold. We prove that if the torsion is parallel and the holonomy is , then the manifold is locally isomorphic to the twistor space of a quaternionic Kähler manifold with positive scalar curvature. If the manifold is complete, then it is globally isomorphic to such a twistor space. 相似文献
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In this paper we investigate Leibniz algebras whose quotient Lie algebra is a naturally graded filiform Lie algebra . We introduce a Fock module for the algebra and provide classification of Leibniz algebras whose corresponding Lie algebra is the algebra with condition that the ideal is a Fock -module, where is the ideal generated by squares of elements from .We also consider Leibniz algebras with corresponding Lie algebra and such that the action gives rise to a minimal faithful representation of . The classification up to isomorphism of such Leibniz algebras is given for the case of . 相似文献